Weaver's cottage
Insulating a traditional cottage roof to better than new build
Martin Smith wanted to plug a major route for loss of heat from his 200 hundred year old cottage overlooking Holmfirth – through the top ceiling. However, the ceiling wasn’t flat, but pitched and held up by timber horizontal beams, making the project more challenging. Above the ceiling, and hidden away, there was some inadequate fibreglass insulation of unknown quality and quantity.
Not impressed by other professional advice he received, Martin approached Bill Butcher at the Green Building Company. Bill suggested inserting insulation between the beams and bringing the roof insulation levels up to a completely modern new build standard.
The work was completed in less than two weeks. A vapour-proof lining was installed under the existing plaster-board, which was then taped for airtightness. Rigid polyurethane board insulation was then screwed to the rafters, sealed using foam sealer, topped with plasterboard and skimmed with plaster. This method meant that the original beams were still visible, with some reduction in depth, but the charm of the house was retained. The final U value for the roof came in at around 0.17 – considerably lower than current building regulations for new build houses of 0.2.
Martin said: “Bill Butcher at Green Building Company was in a different league from the rest in knowing what to do. Other contractors and professionals didn’t seem to know about the best materials and weren’t able to talk U values.”
Completed 2010.
